Coordinate measuring machines (CMMs) are the gold standard for accurately measuring a wide variety of different types of work pieces. For example, CMMs can measure critical dimensions of aircraft engine components, surgical tools, and gun barrels. Precise and accurate measurements help ensure that their underlying systems, such as an aircraft in the case of aircraft components, operate as specified.
Inaccurate measurements can have catastrophic effects. Accordingly, to ensure that CMMs deliver accurate measurements, the CMM industry has developed well-defined accuracy verification standards, procedures, and gauging tools to calibrate and verify the underlying machines taking these measurements. To those ends, a CMM verification procedure typically requires hard gauges that are traceable for uncertainty calculations, and designed in such a way to ensure that they (i.e., the gauges) are dimensionally stable.
More recently, those in the art have begun using computed tomography (CT) systems as CMMs for coordinate metrology. Such CT systems known to the inventors can be subject to a variety of different calibration and verification standards.